OMC 5.8 L twins

[wilksCraft]

Hoping this is the correct place for this.....I have a '93 Chris Craft Crowne cruiser with twin 5.8L motors....periodically when running on the lake at cruising speeds the starboard motor will just quit......kinda fun since the power steering is on the motor and I'm a relatively new boater . After we sit for a few it fires back up.....one guy I talked to said it might be the main electrical harness plug........the guy that's worked on the boat says that it might be the electronics for that model ( maybe requiring a change of the distributor to a newer model) .......anybody have an experience with this kinda thing?

Thanks in advance.

 

[Howard Sterndrive]

Re: OMC 5.8 L twins

It could be all those things and a hundred more, so you'll have to start with some basic checks that all techs do when an engine quits.
1. When it quits, spin the spark plugs out and look for water droplets on them
2. Check compression (you have the plugs out already)
3. Check for spark at the plugs using a spark tester or other means
4. Check for power to ignition system all the way from helm to coil (it could be a bad connection anywhere- even at the helm heating up or a bad ignition switch, safety lanyard switch etc.)
5. Remove fuel filter and see what's in it (full /empty/ water/ dirt etc)
Are these fuel injected motors? If so, check power to ECM too.

 

[wilksCraft]

Re: OMC 5.8 L twins

It could be all those things and a hundred more, so you'll have to start with some basic checks that all techs do when an engine quits.
1. When it quits, spin the spark plugs out and look for water droplets on them
2. Check compression (you have the plugs out already)
3. Check for spark at the plugs using a spark tester or other means
4. Check for power to ignition system all the way from helm to coil (it could be a bad connection anywhere- even at the helm heating up or a bad ignition switch, safety lanyard switch etc.)
5. Remove fuel filter and see what's in it (full /empty/ water/ dirt etc)
Are these fuel injected motors? If so, check power to ECM too.

motors are carbed.......boat had been sitting for 2 years so I had the motors gone thru...new plugs, filters, wires and such....compressions good....we'll start with number 4 next...thanks for the response.

 

[sam60]

Re: OMC 5.8 L twins

I had a similar issue a couple of years ago. It was a 50 Amp breaker that opened when hot and reset after about 10 minutes. It switched the ignition and instrument cluster.

 

[PaJon]

Re: OMC 5.8 L twins

Were the carbs rebuilt ? When it shuts off, is it an instant off or does it sputter then die ?

 

[wilksCraft]

Re: OMC 5.8 L twins

Were the carbs rebuilt ? When it shuts off, is it an instant off or does it sputter then die ?

New carb on the starboard motor....it just shuts off...like you flipped a switch.

 

[wilksCraft]

Re: OMC 5.8 L twins

I had a similar issue a couple of years ago. It was a 50 Amp breaker that opened when hot and reset after about 10 minutes. It switched the ignition and instrument cluster.

I believe we have a winner....sure sounds like that....would explain why after sitting for a few minutes it fires back up....thanks

 

[wilksCraft]

Re: OMC 5.8 L twins

UPDATE.........it ended up being loose connections at the starboard motor ignition switch....along with some corrosion at the switch....funny how things turn out......thanks for the suggestions all.